What is the test of divisibility of 18?

Question

Mila Anderson · Accepted Answer

A number that is divisible by 18 must be divisible by both 2 and 9.  The inverse is also true:
A number that is divisible by both 2 and 9 must be divisible by 18. Therefore, we just have to test for both divisibility by 2 and 9. If a number passes both tests, then it will surely be divisible by 18.

Levi Adams · Answer

Test of divisibility of #18# is that units digit is even i.e. it is either #0,2,4,6# or #8# and simultaneously sum of the digits is divisible by #9#.

Factors of #18# are #2# and #9# and hence divisibility by #18# means divisibility both by #2# and #9#. Divisibility test of #2# being that units digit is divisible by #2# i.e. it is either #0,2,4,6# or #8#. Divisibility test of #9# is that sum of all the digits is divisible by #9#. Hence test of divisibility of #18# is that units digit is even i.e. it is either #0,2,4,6# or #8# and simultaneously sum of the digits is divisible by #9#.

Emery Allen · Answer

undefined A number is divisible by 18 if it is divisible by both 2 and 9. To check divisibility by 2, examine if the number is even (ends in 0, 2, 4, 6, or 8). To check divisibility by 9, find the sum of the digits of the number. If the sum is divisible by 9, then the number itself is divisible by 9. Therefore, to determine if a number is divisible by 18, it must meet both conditions: it should be even and the sum of its digits should be divisible by 9.